test: Document why syncwithvalidationinterfacequeue is needed in tests

test/functional/wallet_importmulti.py

@@ -64,7 +64,7 @@ class ImportMultiTest(BitcoinTestFramework):
         self.nodes[0].generate(1)
         self.nodes[1].generate(1)
         timestamp = self.nodes[1].getblock(self.nodes[1].getbestblockhash())['mediantime']
-        self.nodes[1].syncwithvalidationinterfacequeue()
+        self.nodes[1].syncwithvalidationinterfacequeue()  # Sync the timestamp to the wallet, so that importmulti works
 
         node0_address1 = self.nodes[0].getaddressinfo(self.nodes[0].getnewaddress())
 

test/functional/wallet_resendwallettransactions.py

@@ -49,6 +49,7 @@ class ResendWalletTransactionsTest(BitcoinTestFramework):
         block.solve()
         node.submitblock(ToHex(block))
 
+        # Set correct m_best_block_time, which is used in ResendWalletTransactions
         node.syncwithvalidationinterfacequeue()
         now = int(time.time())